1. Field of the Invention
Present embodiments relate to jig assemblies for coupling of piping. More specifically, the present embodiments relate, but are not limited to, jig assemblies for coupling of thermal plastic piping and methods of positioning a coupling using the jig assemblies.
2. Description of the Related Art
Thermal plastic piping is utilized in a wide array of manufacturing and utility fields. In joining segments of piping, for example in new construction or repair of existing pipes, jig assemblies are utilized to hold piping segments together in order for a welding process or step to occur. Thermal plastic piping may include, but is not limited to, high density polyethylene (HDPE), low density polyethylene (LDPE), acrylonitrile butadiene styrene (ABS), polypropylene (PP), polyethylene (PE), and polyvinylidene fluoride (PVDF), for example.
One problem with the state of the art jig assemblies is related to size of the equipment. Many jigs are utilized which are enormous in size due to the size of the piping involved, for example in water or sewage service lines. When a break occurs in a service line, the area of substrate covering at the break is dug up and the jig assembly must be brought in to retain the pipes in position for a welding process. However, the size of the jig equipment requires that the hole be much larger in size than merely the area immediately surrounding the break. The jig equipment cannot typically fit into a hole and therefore, the cover substrate must be removed so that portions of the broken pipe may be brought to the surface and fitted into the jig assembly.
Another problem with attempts to either join or repair thermal plastic piping is that following initial manufacture and/or use over a period of time, large diameter pipes begin to sag and change shape from round to oblong. This is due to the inability of the material to support the weight of large sized piping. Additionally, soil loads on buried piping may cause this to occur. When coupling sections of pipe together, the oblong shape of the pipe makes welding sections together difficult, for example when welding a new piece of piping to an older piece or when welding pieces that have been stored for some period of time. The oblong shape must be corrected in order to render a pipe a round shape which may be aligned with and welded to another section of piping.
Additionally, one type of pertinent welding involves fusion welding where a small coupling joint material is placed at a joint between two pieces of piping. In large diameter piping, known methods of inserting the coupling on to a first pipe involves a hammer and piece of wood being used to beat the coupling over the end of at least one of the pieces of pipe. This difficulty is in addition to the difficulty associated with oblong shaping of piping and another reason that the piping sections must be positioned into a round shape to allow use with a coupling section. Further, this method provides opportunity for an injury in the field and/or damage to the coupling being forced on to the piping.
Accordingly, it would be desirable to overcome these and other known deficiencies to provide a jig assembly which may be positioned within a hole in the earth for new construction or repair and improves the method of positioning pipe assemblies during welding, for example.